These days, he calls himself Bonnie ‘Prince’ Billy. You might recognize him as Palace Brothers, or Will Oldham, or for the song of his that Johnny Cash covered. An enigma of the folk-rock world — The New Yorker calls him “one of the country’s most celebrated singer-songwriters” despite the fact that he’s never signed with a label — Bonnie ‘Prince’ Billy is hard to find, easy to love, and impossible to dismiss (even if it’s been years since anyone’s had the chance to see him). Call him a DIY folkster with vintage vibes, country cred, and a voice as rich as death. Singing about bottomless heartache and cowboy philosophy, he’s here at MASS MoCA for an intimate and uncensored show this fall. The Louisville folk duo The Other Years warms up the house.